Modified Clavien Classification of our Percutaneous Nephrolithotomy Complications

Aim: To classify and compare the complications we experienced in our percutaneous nephrolithotomies (PCNLs) by using modified Clavien system according to stone type as being simple or complex. Material and Method: Records of our total 210 standard PCNLs performed between May 2010 and April 2014, were evaluated retrospectively. Isolated renal pelvis or calyx stones were considered to be simple stones; partial or complete staghorn stones or renal pelvis stones accompanying caliceal stones were considered to be complex stones, regardless of their size. Results: The patients were all adults (77 females and 133 males). Mean age was 46.74 ± 13.40 (18-76) years. A total of 126 patients (60%) had simple and 84 patients (40%) had complex kidney stones. Mean stone area and operation time were 466.50 ± 361.81 (60-1900) mm2 and 81.02 ± 24.99 (45-165) min, respectively. All operations were completed with the application of a nephrostomy tube and mean nephrostomy tube removal time was 2.98 ± 1.23 (1-9) days. Complications were encountered in 36.5% of simple stones and 65.5% of complex stones. A statistically significant difference was detected between simple and complex stone groups with regard to PCNL complications (P = 0,0001). Discussion: Morbidity of PCNL is higher in complex stones compared with simple stones. Modified Clavien is a practical grading system for reporting complications of PNL procedures